1. Field of the Invention
The present invention relates to a power supply unit for a portable game machine, and more particularly, to a universal power supply unit for the game machine model of Nintendo Game Boy Advance.
2. Description of the Prior Art
The Nintendo Game Boy machine is portable due to its small volume so that the Nintendo video games are widely popular. The current model of the game machine 1 (Game Boy Advance), as shown in FIGS. 1 and 2, has a battery chamber 11 at the bottom thereof in which two dry batteries 12 are received for supplying 3V DC voltage to the game machine. Besides, a cover 13 is engaged in the battery chamber 11.
The power of the game machine 1 is much consumed so that two dry batteries 12 can only be used for few hours. After the batteries have run down, they have to be replaced, thereby causing a considerable cost. In order to resolve this problem, a power transforming unit 2, as shown in FIG. 3, is installed in the battery chamber 11 in addition to the design of power supply by batteries. The power transformer 2 includes a transformer connector 21 which transforms the main power to 3V DC voltage which passes through a cover 22 engaged in the battery chamber 11, utilizing the electric contact between the positive and negative output poles 221 at the side of the cover and the positive and negative poles 111 inside of the battery chamber 11 for supplying the required power to the portable game machine 1.
However, the cover 22 and the transformer connector 21 of the power transformer 2 have special specification. In other words, the DC jack 222 on the cover 22 is only suitable for the connecting terminal 211 of the transformer connector 21 manufactured by Nintendo. Besides, the output of the transformer connector 21 is preset at 3V DC voltage. Thus, the inside of the cover 22 only has a filtering inductance L1 and a diode D1. Therefore, the cover 22 doesn""t fit other power supply units, for example, the DC 12V power supplied from the cigarette lighter in automobiles. Moreover, there are no mains sockets in automobiles for the transformer connector 21. Thus, much inconvenience in use is still existing.
It is a primary object of the present invention to provide a power supply unit for a portable game machine which is engaged in a cover of a battery chamber and contains a constant voltage loop. Besides, the power supply unit can be used in combination with commercially available transformers so that the convenience in use is much improved.
It is another object of the present invention to provide a power supply unit for a portable game machine in which the circuit devices have advantages of convenient assembly, stable structure and excellent electric contact.